1. Field of the Invention
The present invention relates to a meniscectomy by an arthroendoscopical surgical method of treating a meniscus by using an ultrasonic treatment tool under arthroendoscopy.
2. Description of the Related Art
There is known a surgical operation which is generally called arthroendoscopical surgery. In the arthroendoscopical surgery, two or so small holes (external portals) are opened in the skin near an articulation. A rigid scope, which will serve as an arthroscope, and a therapeutic device, are inserted from the external portals (or portals). Treatment is performed while confirming video which is displayed on a monitor in a state in which the inside of the articulation is filled with perfusion liquid for articulation surgery.
For example, as disclosed in patent document 1 (US2015/0297073), the arthroendoscopical surgery is applicable to a surgical operation for administering surgical treatment to a meniscus. Endoscopical surgical methods using arthroscopes for menisci are generally classified into resection surgery which resects an injured denatured part of a meniscus, and suture surgery which sutures a denatured part. Either resection alone or suture is selected in consideration of a diagnosis result based on various conditions such as a form of tear, a part of tear, or the presence/absence of a blood flow in an injured part of a meniscus.
In conventional endoscopical meniscus surgery, the rigid scope or therapeutic device is inserted in an articulation from the above-described portal, and a denatured part of the meniscus is resented by a tool such as a punch or a shaver under observation by the arthroscope.
As will be described later, a meniscus includes an area in which blood flows and an area in which no blood flows. The area in which blood flows is further divided into an area where blood vessels are dense, and an area where blood vessels are sparse. On the outer peripheral side of the meniscus, there is a dense blood flow area A where many blood vessels (blood flows) exist. In the middle part, there is an area B [vascular area: sparse blood flow area] where blood flows, although fewer than in the area A [vascular area: dense blood flow area], exist. In the inner side of the area B, there is an area C [no-vascular area: no-blood-flow area] where no blood flow exists.
When the above-described denatured part of the meniscus is resented, it is required to exactly resect the denatured part, and to resect only the no-blood-flow area, so as not to cause damage to the other part.
However, in the resection by conventional art, there are considerable physical and chemical effects, such as over-cutting of a resection surface and damage due to heat, and a surgeon has to pay close attention.
In addition, there are unclear points with respect to the condition of the end face of the displayed meniscus (e.g. whether a denatured part was resected or not, and whether vascular exists or not), and it is difficult to determine how far the resection should be performed, and skill is required for the determination.
Furthermore, FIG. 9A illustrates stress acting on a normal meniscus from a thighbone. On the other hand, as illustrated in FIG. 9B, by resection by a tool such as a punch, a cut surface, which is perpendicularly cut from an upper face of a curved surface of a meniscus, is formed, and a corner portion occurs. Stress tends to easily concentrate at the corner portion from the spherical contact surface of the thighbone.
When such a corner portion or irregularities occur on the cut surface, it is necessary to additionally perform resection or trimming for adjustment, thereby adjusting the cut surface of the meniscus. However, depending on the position of a treatment site, a sufficient treatment space cannot be acquired, and there may be a case in which proper adjustment cannot be implemented.